Heating unit



ch 194s.

J. E. BRIGGS HEATING UNIT Filed March 23. 1937 Q m S S l -1 H ,n I T/ Il y u m Q w I l l L il v l H 1' il .J y l I I 9 i l 312 l Y l H I I 2 Sheets-Sheet l INVENTOR.

ATTORNEY.

March 5 1940- J. E. BRIGGS 2,192,636

` HEATING UNIT Filed arch 25, 1937 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Patented Mar. 5, 1946 PATENT OFFICE HEATING UNIT John E. Briggs, Detroit, Mich.

Application March 23,

'i Claims.

This invention relates to furnaces and more particularly to an improved hot air furnace structure and to a novel heating apparatus therefor.

An important object of this invention is to provide a novel flue structure for a furnace including a novel control therefor for regulating the heat transfer between the hot combustion gases conducted from the combustion chamber by the ue and the room air which it is desired to heat. The iiue is constructed in a novelmanner to provide on the one hand a short direct passage for the combustion gases, and on the other hand a long tortuous path for the combustion gases, or any degree between these extremes. Room air which it is desired to heat is passed in surface contact with the flue structure, and theA amount of heat transferred from the iiue to the room air varies in direct proportion to the extent of the path provided in the iiue structure for the conduction of the hot combustion gases. It is possible therefore as a result of this invention to regulate with nicety the degree of heat transfer between the hot combustion gases and the relatively cool room air which it is desired to heat.

More specifically, the invention contemplates a flue structure opened at one end for communication with the combustion chamber of the fur-v a novel fashion for varying the path of the exhaust gases and thus varying the amount of heat transference between the air in the casing and the exhaust gases in the ues. Provision is made for admitting fresh air to the casing and discharging air warmed therein from the top of the casing. A novel deector construction is provided within the casing for directing the fresh air admitted thereto into close proximity with the walls of the flues.

Other objects, advantages and meritorious features of this invention will appear more fully from the following specification, appended claims and accompanying drawings, wherein:

Fig. l. is a cross-sectional view of a hot air furnace from front to rear showing the location and construction of the various features of the 1931,- serm No. 132.515

(ci. 12a-.99)

invention and the-manner in which they cooperate with one another,

Fig. 2 is a front end view of the hot air furnace illustrated in Fig.- l partly broken away to show the interior construction of the furnace g along line 2-2 of Fig. l,

Fig. 3 is a detail view of the fiue construction along line 3-,3 of Fig. 2.

Referring more particularly to the drawings; the furnace structure comprises a shell or` casw ing I0 surrounding the furnace proper indicated generally by the reference numeral I2. As is customary, the casing I0 is mounted in spaced relationship to the furnace I 2 in order to form an air chamber between these two units. In the embodi- 15 ment of the invention illustrated herein the casing is spaced from the furnace in the rear and on the opposite sides thereof, the front of the casing and the furnace coinciding so that access may be had to the doors of the furnace. Air isconducted from the rooms of the building in which the furnace is located by an air duct I4 and by means of a fan located in the fan housing I6 this air may be forced into the .bottom of the air chamber formed by the casing and the furnace units. The top of the casing is provided with a discharge outlet I8 as shown and any suitable air duct may be connected thereto for conducting the air in the casing to the rooms which it is desired to heat. so

The furnace unit I2 includes a heating apparatus generally indicated at 20 and a combustion chamber 22 into which the heating apparatus discharges the ames of combustion. As shown in the drawings the bottom of the furnace is provided with a base foundation 24 of any suitable fire resisting material. A circular recess 26 is formed in the front section of this material and.

f the heating apparatus 20 is disposed therein.

The hot products of combustion'are conducted away from the combustion chamber by a novel system of ilues. The top of the combustion chamber is closed off by a plate 28 having a slightly inverted V-formation as best shown in Fig. 2. 'Ihis plate extends from the front of the 45 furnace to a point slightly spaced from the rear wall 30 of the furnace. A partition 32 rises vertical from this point and forms, in conjunction with the rear wall 30, a passage 34 leading upwardly from the rear of the combustion chamber. 50 Extending from the rear wall 30 to the partition 32 are a pair of oppositely facing, slightly inclined elements 35 and 36 joined together with the top of the plate 32 to form a diamond-shaped air duct 38 as best shown in Fig. 2. Both the rear wall 55 30 and the partition 32 are apertured at the opposite ends of the duct $8 and air rising in the casing l0 can iiow through this duct to the front side of the partition 32. The air duct 38 divides the passage 34 into two vertical ues 40 and 42 which diverge slightly around the diamondshaped air passage 38 as they rise from the oombustion chamber and then converge and join together in the upper part of the casing. An exhaust pipe 44 extending rearwardly from the furnace and casing opens into the vertical ues 40 and 42 at their juncture.

The partition 32 is pierced at three places in the embodiment of the invention disclosed herein to provide circular openings into which the open ends of three horizontal cylindrical ues may be positioned. Obviously, the number as well as the size of these cylindrical ilues may be varied to suit different conditions. In the embodiment of the invention disclosed herein a circular opening is provided in the top of the partition 32 opposite the exhaust pipe 44 and two more of such openings are provided below and upon opposite sides thereof, one opening into each vertical ilue 40 and 42. The three openings are therefore arranged in triangular formation as Fig. 2 will show.

As previously explained, a cylindrical-shaped flue is supported in each of the three openings in the partition 32. These fiues extend forwardly of the partition 32 in horizontal parallel relationship. They therefore form a triangular or pyramidical ue construction in the space above the plate 28 of the combustion chamber. The two cylindrical ues on opposite sides of the partition are numbered 46 and 48. The top cylindrical flue is numbered 50. The top cylindrical flue is preferably of larger diameter than the two lower ues as shown in Fig. 2 in order to accommbdate the products of combustion of both of the vertical ues 40 and 42. The front ends of these cylindrical ues project through the front wall of the furnace I2 where they are supported..

In each of the cylindrical ues is a deecting element or baille plate. For each` cylindrical ue 46, 48 and 50 the baille plate is numbered respectively as 52, 54 and 56. The baflie plates are preferably of a width slightly less than the diameter of the flue in which it is positioned and of a length substantially equal to the length of its respective ilue. These baille plates are supported in their respective flues by merely bearing upon the inner wall surfaces of the iiues. Since they have a width slightly less than the diameter of their respective flues they extend substantially diametrically across the ilue as shown in Fig. 2 and divide the same into upper and lower compartments of almost the same size. The manner of supporting the baille plates in the cylindrical ilues permits them to be adjusted longitudinally therein and, as shown in Fig. 1, they maybe adjusted so as to project into thezvertical flues 40 and 42 while the front ends of the baille plates are spaced inwardly from the front end ot'. the cylindrical ues.

Each cylindrical flue is closed at its front end by a removable closure member or door. Two of such doors are shown at 58 and 60 in Figure 1. 'Ihese .doors permit access to the interior of the cylindrical '.fiues and enable one to reach the b'afile plates and adjust them longitudinally in their respective ues. These doors also permit one to gain access to the cylindrical ilues for cleaning Purposes.

The operation of the bale plates 52, 54, and 58 is easily understood from the arrows in Fig. 1 indicating the paths of the burnt combustion gases. When the bale plates project ino the vertical ues 40 and 42 they deect some of the products of combustion into their respective ilues as shown in Fig. 1. As indicated by the arrows, the products of. combustion deiiected by these bale plates are directed forwardly through the lower compartment of each cylindrical flue, then upwardly at the forward end thereof and thence rearwardly through the upper compartment of each flue. The amount each baille plate projects into the vertical iiues 40` and 42 determines in like proportion the volume of hot combustion gases its respective cylindrical flue will receive. When the baille plates project into the vertical ues until they abut or almost abut the rear wall 30 of the furnace, a long tortuous path is provided for conducting all of the hot combustion gases from the combustion chamber to the exhaust pipe 44. However, when'the bafie plates are adjusted to positions entirely within their respective flues, the vertical flues 40 and 42 are opened and a short direct path is provided for exhausting the combustion gases rising from the combustion chamber. Obviously, the baille plates may be adjusted to positions intermediate these two extremes.

The fresh room air directed by the fan into the bottom of the casing l0 rises into surface contact with the heated walls of the furnace and the iiues. The degree to which this room air is heated is varied by the area and the temperature of the heating surface with which it comes in contact. Adjustment of. the baille plates in their respective flues will vary the amount of hot combustion gases deflected therethrough and as a result vary the temperature of the walls of these ilues and the area of heated surfaces presented to the room air in the casing. Some of the fresh room air enters the diamond-shaped duct 38 and passes into the highly heated area in the center of the triangular formation formed by the cylindrical ues. Some of the fresh room air rises along side of the furnace and thence into contact with the vertical and horizontal iiues. In order to direct the greater portion of the air rising in this manner into direct contact with the cylindrical ues, a pair of deflector elements 62 and 64 on opposite sides of the furnace may be provided. The upper ends of these elements are curved inwardly in order to deflect the rising currents of air toward and under the cylindrical ues as shown in` Fig. 2. The deflector elements 62 and preferably extend from the front wall to the rear wall of the casing I0.

As shown in the embodiment of the invention illustrated herein, the baffle plates in the cylindrical flues are of slightly less width than the diameter of the flues. The purpose of this construction is to provide openings for the upward escape of gas in case of an explosion or the creation of an undue gas pressure in the combustion chamber in some other manner. In the event such a sudden pressure is created, the baille plates are able to rise and provide clearances along both of their side edges to permit the escape of the gas and as a result instantly lessen the pressure of gas.A The heating apparatus for the furnace illustrated herein is an oil burner type. It comprises a number of elements associated together to form a mixing chamber shaped in the formation of a bowl having a smaller discharge outlet than the interior thereof. A blower 94 driven by a motor 96 delivers air to the4 burner through air pipes i4 and fuel pipe 82 delivers fuel to the burner from a suitable source. The construction and operation of the burner forms no part of this particular invention other than that a burner of suitable structure is required.

What I claim:

l. A. hot air furnace structure comprising, in combination, a casing having an air inlet adjacent the bottom and an air outlet adjacent the top and a communicating connecting air passageway, a furnace within said casing having a combustion chamber and a vertical ue rising vertically from the rear of said combustion chamber, a plurality of horizontally mounted cylindrically-shaped iiues opening into said vertical iiue and vextending forwardly therefrom over the combustion chamber of the furnace, means sealing the forward ends of said horizontal ues, and a bae plate in each of said horizontal ilues mounted for longitudinal slidable movement therein and adapted to project beyond its respective horizontal flue into said vertical ue for the purpose of deiiecting exhaust gases rising in said vertical iiue into its respective horizontal ue and an air conduit leading from said communicating air passageway through said vertical flue and discharging between said plurality of horizontally mounted iiues.

2. A hot air furnace comprising, in combination, a combustion chamber, a pair of spaced vertical fiues leading from said combustion chamber for conducting hot combustion gases therefrom and joining at their upper ends to form a common conduit for conducting the combustion gases, a horizontal iiue having one end opening into said vertical flues at the point of their juncture, a horizontal ue for each vertical flue having one end thereof opening into its respective vertical flue at a point below the juncture of the vertical fiues, a closure member for each of said horizontal iiues removably secured to the opposite ends of said horizontal ues and when closed sealing the horizontal ilues against the escape of combustion gases therewithin, a plate element in each of said horizontal flues dividing each of the same into upper and lower compartments, said plate elements being longitudinally adjustable in their respective flues and adapted to project varying distances across the passages of said vertical fiues to regulate the amount of the combustion gases deflected into the horizontal ues, and a casing surrounding said combustion chamber and said fiues having an air inlet adjacent the bottom and an air outlet adjacent the top above the juncture of said vertical ues.

3. A hot air furnace comprising, in combination, a combustion chamber, a pair of spaced vertical iiues leading from said combustion chamber for conducting hot combustion gases therefrom and joining at their upper ends to form a common conduit for conducting the combustion gases, a horizontal ilue having one end opening into said vertical ues at the point of their juncture, a horizontal ue for each vertical ue having one end thereof opening into its respective flue at a point below the juncture of the vertical ues, a closure member for each of vsaid horizontal ues removably secured to the opposite ends of said horizontal iiues and when closed sealing the horizontal ilues against the escape of combustion gases therewithin, a plate element in each of said horizontal fiues dividing each of the same into upper and lower compartments, said plate elements being longitudinally adjustable inv their respective flues and adapted to project varying distances across the passages of said vertical flues to regulate the amount of combustion gases deflected into the horizontal iiues, a casing sur- 4. A hot air furnace structure including, in

combination, a vertical iiue for conducting hot combustion gases, a horizontal flue having one end thereof opening into said vertical iiue, means for sealing the other end of said horizontal ue against the escape of combustion gases therewithin, a plate having a width slightly less than the transverse dimension of the horizontal flue and a length less than the combined length of the horizontal ue and horizontal dimension of said Vertical flue, said plate arranged within said horizontal flue on substantially a horizontal plane dividing the horizontal flue into vtop and bottom compartments, and supported for slidable movement longitudinally within said horizontal and transversely of said vertical flue and adapted by reason of the fact that its length is less than the combined length of the horizontal and vertical fiues to present openings of variable sizes at either or both ends of the'plate to regulate the amount of the combustion gas iiowing from the vertical flue through the compartments of said horizontal flue, said plate supported within the horizontal ue for vertical movement within the horizontal flue for escape of gas from the lower to the upper compartments Within the horizontal ue along the longitudinal margins of the plate.

5. A hot air furnace comprising, in combination, a combustion chamber, a vertical ue for conducting hot combustion gases from said chamber, a horizontal cylindrical flue having one end thereof opening into said vertical flue, a baille plate of slightly less width than the diameter of said cylindrical flue extending longitudinally therethrough, said baille plate dividing the flue into upper and lower compartments and being shiftable vertically within the flue to provide for the escape of gas directly from the lower into the upper compartment along the longitudinal edges e of the plate.

6. A hot air furnace comprising, in combination, a casing having an air passageway therethrough provided with an air inlet at the bottom and an air outlet at the top, a. furnace within said casing having a combustion chamber providedv with a vertical exhaust flue, a pair of horizontally spaced horizontal ues superimposing said combustion chamber and each communicating with the vertical flue at one end and closedat its opposite end, and a third horizontal flue superimposing the space between said pair of flues and communicating with the vertical iiue at one end and closed at the opposite end, a partition extending irom the vertical iiue over the combustion chamber spaced below said pair of flues, a baille plate extending longitudinally through each horizontal ue of said pair dividing the same into communicating upper and lower compartments,

an air conduit extending from the air passage! way through the casing through said vertical ue into the space above said partition between said horizontal flues, and dividing said vertical ue,

into two vertical compartments, one of said compartments communicating with one of the horizontal iiues of said pair and the other compartment communicating with the other horizontal flue of said pair.

7. A hot air furnace comprising, in combination, a casing having an air inlet at the bottom and an air outlet at the top. a furnace disposed Within said casing having an enclosing wall spaced f rom the side wall of. the casing providing an air passageway about the furnace within the casing, said furnace including a combustion chamber having a. vertical exhaust iiue provided with an outlet, a partition superimposing said combustion chamber, a plurality of horizontal exhaust ilues superimposing said partition and each communicating at one end with said vertical ex- J ORN E. BRIGGS. 

